<?php

/**
 * Add A Setting Page: Admin > Tools > My Custom Plugin
 */
function wpdocs_plugin_admin_menu() {

	add_submenu_page( 'tools.php', __( 'My Custom Plugin' ), __( 'My Custom Plugin' ), 'manage_options', 'wpdocs-plugin-slug', 'wpdocs_pages' );

}
add_action( 'admin_menu', 'wpdocs_plugin_admin_menu', 9999 );

/**
 * This handles which template loads based on the GET vars
 */
function wpdocs_plugin_pages() {

    global $current_user_id;

    if ( ! current_user_can( 'manage_options' ) ) {
        wp_die( 'You do not have permission to view this page.' );
    }

    $tab = $_GET['tab'] ?? '';

    echo '<div class="content-body">';

	// Load the header nav
	wpdocs_plugin_header();

	if ( in_array( $tab, array( '', 'dashboard' ) ) ) {

		// Load Dashboard
		wpdocs_plugin_dashboard();

	} elseif ( 'another-page' === $tab ) {

		// Load Another Page
		wpdocs_plugin_another_page();

	} else {

		echo '<p>' . __( 'Error: Couldn't find the page you are looking for.' ) . '</p>';

	}

    echo '</div>';
}


/**
 * Loads the scripts needed on the Dashboard page
 */
function wpdocs_plugin_scripts() {

	$page = $_GET['page'] ?? '';
	$tab = $_GET['tab'] ?? '';


	// This condition is assumes you will have more than 1 page for your plugin's admin area
	// The other pages of your admin would be relying on $_GET['tab']
	if ( 'wpdocs-plugin-slug' === $page && in_array( $tab, array(
		'',
		'dashboard',
	] ) ) {

		wp_enqueue_script( 'dashboard' );
		wp_admin_css( 'dashboard' );
		add_thickbox();

	}

}
add_action( 'admin_enqueue_scripts', 'wpdocs_plugin_scripts', 9 );


/**
 * Registers the dashboard widgets to be displayed
 */
function wpdocs_plugin_register_widgets() {

	wp_add_dashboard_widget( 'wpdocs_plugin_widget_1', __( 'Custom Widget 1' ), 'wpdocs_plugin_widget_1', null, null, 'normal' );
	wp_add_dashboard_widget( 'wpdocs_plugin_widget_2', __( 'Custom Widget 2' ), 'wpdocs_plugin_widget_2', null, null, 'side' );
	wp_add_dashboard_widget( 'wpdocs_plugin_widget_3', __( 'Custom Widget 3' ), 'wpdocs_plugin_widget_3', null, null, 'side' );

}


/**
 * Creates the display code for the custom widget
 */
function wpdocs_plugin_widget_1() {
	?>

	<p>Custom widget 1 info here</p>

	<?php
}

/**
 * Creates the display code for the custom widget
 */
function wpdocs_plugin_widget_2() {
	?>

	<p>Custom widget 2 info here</p>

	<?php
}

/**
 * Creates the display code for the custom widget
 */
function wpdocs_plugin_widget_3() {
	?>

	<p>Custom widget 3 info here</p>

	<?php
}

/**
 * Header of the admin templates
 */
function wpdocs_plugin_header() {
	// Add your own styling so that it will look better
	?>
	<nav>
		<ul>
			<li><a href="<?php echo esc_url( admin_url( 'tools.php?page=my-custom-plugin-slug&tab=dashboard' ) ); ?>">Dashboard</a></li>
			<li><a href="<?php echo esc_url( admin_url( 'tools.php?page=my-custom-plugin-slug&tab=another-page' ) ); ?>">Another Page</a></li>
		</ul>
	</nav>
	<?php
}

/**
 * Another Page Template
 */
function wpdocs_plugin_another_page() {
	?>

	<h1>Another Page</h1>
	<p>Custom content goes here.</p>

	<?php
}


/**
 * This displays the template for the dashboard for my custom plugin
 */
function wpdocs_plugin_dashboard() {
	// Load the admin dashboard code from core
	require_once ABSPATH . 'wp-admin/includes/dashboard.php';

	// Register Widgets TO Be Displayed
	wpdocs_plugin_register_widgets();
	?>

	<h1>My Custom Dashboard</h1>
	<div class="wrap">

		<div id="dashboard-widgets-wrap">

			<?php
			// Display Widgets
			wp_dashboard();
			?>

			<div class="clear"></div>
		</div><!-- dashboard-widgets-wrap -->

	</div><!-- wrap -->
	<?php
}